When I was a lad I used to collect the little cards that come with packs of Brooke Bond teas. When I was collecting they came in sets of 50, one was Prehistoric Animals and one was Inventors and Explorers. I particularly remember one called the "The Sea - Our Other World".
I was reminded about this by a couple of stories I've read recently.
For example last nights Natural World on BBC 2 featured Dr Andrea Marshall who has identified a new species of Manta Ray. The Manta is a Giant Manta which can grow up to 7m wide. Dr Marshall has ascertained that the Manta's dive deeply, and migrate 700 miles in just 60 days to the Maldives, the longest migration known for a fish living in the Indian Ocean.
Two sponge species, one previously unknown to science and one new to the UK, have been discovered during a diving expedition in UK waters. The marine sponges were discovered in the Isles of Scilly and examined by Dr Claire Goodwin, from National Museums Northern Ireland, they were found during a week of exploratory diving as part of a Seasearch survey.
And the deepest living fish ever spotted in the southern hemisphere have been caught on camera. The fish were photographed at a depth of 7,560m (24,800ft), swimming in the Kermadec Trench off the coast of New Zealand.